Legislation has been enacted requiring child-proof caps for containers of harmful or dangerous ingredients, such as liquid or powder or pill medicines or acids, etc. Many different safety caps have been designed to be tamper-proof. Most ideas involve a driver which rotates freely on the cap in an unscrewing direction and employs special manipulation or means not known to the child, whereby the driver may be caused to unscrew the cap from the container.
Such designs are shown in the patents to Haynes U.S. Pat. No. 2,994,447, Thornton U.S. Pat. No. 3,019,931, Mumford U.S. Pat. No. 3,147,873, Peterson U.S. Pat. No. 3,394,829, Petronelli, et al. U.S. Pat. No. 3,669,294, Gach U.S. Pat. No. 3,679,085, Gach U.S. Pat. No. 3,722,727, Taylor U.S. Pat. No. 3,729,110 and DeFelice U.S. Pat. No. 3,734,331.
There is a remote danger that in the original bottling operation the cap will not be tightly screwed in place, or of an adult, when using the medication or pills or dangerous ingredient, to be in a hurry or through inadvertence not to rescrew the cap tightly in place, with the result that a child playing with the container or trying to remove the cap, will, because of its looseness, get the cap off the bottle.
There is, therefore, a need for a simple, effective means which will assure that in these cap assemblies having the driver element which encloses the cap, which will give a signal that the cap is or has been tightly secured in place. With such a device the danger of a child removing the cap will be reduced to a minimum.